Renewable fuse plug



Sept. 4, 1923.

D. C. HUBBARD RENEWABLE FUSE PLUG Filed June'22 1921 lrrue tor.- Do n QJL Hubba d,

l swmm Patented Sept. 4, 1923.

UNITED STATES DON cameos nonmmn, or AUBURN, MAINE.

RENEWABLE FUSE PLUG.

Applicationflled June 22,1921. Serial No. 479,637.

To all whom it may concern:

Be it known that I, Don CARLQS HUBBARD, a citizen of the United States,residing at Auburn, in the county of Androscoggin and State of Maine,have invented certain new and useful Improvements in Renewable FusePlugs, of which the following is a specification.

My invention relates to a renewable fuse plug in which the fusible stripwhen burned out or melted can be quickly and easily replaced without thedestruction of the entire plug, by simply putting in a new strip of Ifinal y appears in the plug and,

fusible metal, the body of the plug remaining intact.

The advantage of this renewable plug is that it is only necessary tocarry in stock a supply of the fusible metal strips and when a plug isburned out it is only necessary to put ina new strip which can bequickly and easily done.

According to my invention, my plug is constructed in its preferableform, of a hollow socket open at the top with an enlargement at theupper end forming a shoulder at the upper portion of the socket properin which are formed a pair of recesses or depressions. A fusible metalstrip extends across from one recess to the other, connecting in onerecess with a contact strip which extends to the bottom of the socketand there connects with a headed rivet while the other end of thefusible strip connects in the opposing recess with a screw threadedsleeve which occupies the lower end of the socket with a connectingcontact strip extending from the outside into said recess.

The ends of the'flexible strip are turned up and tucked into openingsformed in the lower end of a stopper provided with downwardly extendingprojections adapted to hold the ends of the fusible strip firmly incontact with the contact strips.

The sto per is held in place by a screw threaded s eeve fitting over theenlarged up per end of the plug.

I have illustrated my invention by means of the accompanying drawing inwhich is shown a renewab e fuse plug as I prefer to construct it but itis to be understood that the invention may be constructed otherwise thanas here shown.

Referrin to the drawing:-

Fig. 1 s ows a central vertical section taken on the line 11 of Fig. 2,

Fig. 4 1s a side elevation of the stopper with a portion in section,

Fig. 5 is a side elevation of the stopper "at right angles to theposition shown in Fig. 4,

Fig. 6 is a section through the stopper 1 taken on the line 6-6 of Fig.5,

Fig. Tie a plan of the fusible metal strip, Fi 8 is t e same bent intoform as it on the line 9-9 of socket is hollowed out in the form of acylindrical opening 4 terminating at its upper end in an enlargementforming a shoul der 5 in which are formed a pair of downwardly extendingrecesses 6 and 9. The u per cylindrical portion is, as here shown, the

same diameter as the outer portion of the recesses from 6 to 9.

The upper end of the contact strip 7 is turned out horizontally and lieswithin the recess G and the other contact strip 8 which is positioned onthe outside of the socket 2 extends upward through a suitable opening 10and inward to a position within the recess 9. The lower end of thecontact strip 7 is connected with a suitable rivet or screw extendingthrough the bottom of the socket and having a fiat head 12 for makingthe central electrical connection.

The contact strip 8 is soldered or otherwise connected with a screwthreaded sleeve 13 which fits over and includes the screw threaded endof the socket for screwing the same into place in the opposite femalesocket A hollow stopper 14 fits within the cylindrical space in theenlargement 3 and it has a pair of downwardly extending projections 15which extend into the recesses 6 and 9. The fusible metal strip 16 isformed with two fiat ends and a fiat portion in the center upon whichmay be stamped the standard amperage of the strip.

The flattened ends of the strip 16 are bent in such a way that the innerends of the of a screw flattened portion lie on the lower surface 01'the projection 16, thence extending up on the outside of the stopper, itentersthe opening 17. The strip which is somewhat longer than the directdistance between the pcsite recesses is bent upward into the ho lowortion of the stopper and assumes when in osition the she is shown inFig. 8. r

The strip is dtted into the head solidly before the latter is slippedinto the opening in thenpper end of the socket.

The stopper is pressed downward firmly clamping the ends of the fusiblestrip against the two ends of the contact strips by means threadedsleeve 18 fitting on a screw threaded surface of the enlargement 3 andhaving an inwardly extending annular flange 19 fitting over the head 20of the stopper and resting on a shoulder 21 formed at the base of thehead.

Thus, in order to supply the fusible plug with a fusible strip, it isonly necessary to stick one of the ends into the opening 17 in thestopper, bring the strip down around the lower end of the projection 15across over the opposite projection 15 thence up ward and insert it intothe opposite openin 17.

he stopper thus prepared is put in place, the projections 15 slippinginto the two recesses 6 and 9, and the whole is forced downward by ascrew threaded sleeve 18 clamping the fusible strip firmly against thetwo contact strips. 7

The stopper, as well as the socket, is constructed of insulated materialas porcelain and the entire device constitutes a fuse plug cheaply madeand easily renewable so that the user does not need to carry a varietyof completed plugs but can make use of a single plug with a variety offusible strips according to the amperage required.

I claim 2- 1. In a renewable plug, the combination of a hollow socketopen at one end with an enlargement at said end forming an annularshoulder, a pair of recesses being formed in said shoulder, a contactrivet extending through the lower end of the socket, a contact stripwith its lower end connecting with said rivet and its upper end lyingwithin one of said recesses, a screw threaded sleeve on the lower end ofthe socket, a contact strip connecting with the said sleeve and with itsupper end lying in the other recess, a hollow stopper for filling theenlarged upper end of the socket having projections fitting into saidrecesses, a fusible strip extending from one of said recesses to theother and held in place by said projections and means for holding saidstopper in place.

2. In a renewable plug, the combination of a hollow socket open at oneend with an enlargement at said end forming an annular shoulder, a pairof recesses being formed in said shoulder, a contact rivetextendingthrough the lower end of the socket, a contact strip with its lower endconnecting with said rivet and its upper end lying within one of saidrecesses, a screw threaded sleeve on the lower end of the socket, acontact strip connecting with the said sleeve and with its upper endlying in the other recess, a hollow stopper for filling the enlarged uper end of the socket having projections tting into said recesses, aslot being ,formed through the socket above each projection, a fusiblestrip extending from one of said reeessesto the other and held in-placeby said rojections and with its ends extending t rough said slots frominside outwardly and means for holding said stopper inplace.

3. In a renewableplug, the combination of a hollow socket open at oneend with an enlargement at said end formin an annular shoulder, acontact rivet exten ing through the lower end of the socket, a contactstrip with its lower end connecting with said rivet and its upper endlyington said shoulder, a screw threaded sleeve on the lower end of thesocket, a contact strip connecting with the said sleeve and with itsupper end 1 ing on said shoulder, a hollow stopper for ii in theenlarged upper end of the socket a resting on said shoulder, a fusiblestrip extending from one side of said shoulder to the other tounite'said contacts and held in place by said stopper and means forholding said stopper in place.

DON CARLOS HUBBARD.

